The goal of the proposed research is to improve predictions of speech recognition and listening effort for children based on the Speech Intelligibility Index (SII). The SII is a single number used to quantify the average audibility of speech stimuli under different listening conditions and is often used to optimize hearing aid settings for children. SII calculations are based on frequency-importance weights (FIW), which place a numerical value on the contribution of a specific frequency range to speech recognition. Despite previous studies demonstrating that children require more high-frequency information than adults to achieve optimal speech understanding, FIW based on data from normal- hearing adults are currently used to estimate speech recognition of children. Studies have suggested that adult-based predictions overestimate performance for children, which could lead clinicians to select hearing-aid characteristics that do not provide an optimal basis for speech and language development. FIW have not been specifically measured with children in previous studies, and the relationship between audibility and listening effort in children remains undetermined. In Aim 1 of the proposed research, FIW will be measured for normal-hearing adults and children in an effort to improve SII- based predictions of speech recognition for children. In Aim 2, the child-derived FIW will be used to predict speech recognition and listening effort in a new group of normal-hearing children. It is hypothesized that FIW will differ for adults and children and that child-derived FIW will result in more accurate predictions of speech recognition and listening effort than the current SII. PUBLIC HEALTH RELEVANCE: The results of the current proposal will enhance selection of hearing-aid signal processing for children with hearing loss to focus on maximizing speech understanding and minimizing listening effort. Our understanding of how adults and children differ in their ability to use spectral cues for speech perception will also benefit from the results of the current proposal. Further improvements in amplification strategies for children with hearing loss could result in better outcomes in speech and language development.